1. Field of the Invention
The present invention relates to a musical tone synthesizing apparatus which is suitable for synthesizing a musical tone of a string-striking-type instrument such as a piano and a string-plucking-type instrument such as a guitar.
2. Prior Art
Conventionally, there is a known musical tone synthesizing apparatus which activates a simulation model for the musical tone generation of the non-electronic musical instrument to thereby synthesize sounds of the non-electronic musical instrument. The conventionally known musical tone synthesizing apparatus, which is designed to synthesize sounds of the percussion-type instrument or string-plucking-type instrument, has a configuration including a loop circuit and an excitation circuit. Herein, the loop circuit further includes a delay circuit simulating the propagation delay of vibration of the string and a filter simulating the acoustic loss to be occurred by the string. In addition, the excitation circuit supplies an excitation signal to the loop circuit, wherein this excitation signal corresponds to an excitation vibration to be occurred when plucking or striking the string. The above-mentioned apparatus is disclosed in Japanese Patent Laid-Open Publication No. 63-40199 and Japanese Patent Publication No. 58-58679, for example.
In general, the piano provides plural strings with respect to each key. Strictly speaking, each string has a different tension characteristic, so that each string may produce a slightly different pitch. As a result, unique sounds can be sounded from each piano. More specifically, a vibration energy applied to each string propagates toward another string via a fret portion. Therefore, "mutual interference" is made between the strings via the fret portion, so that the piano can produce a sound having a delicate fluctuation. Herein, the mutual interference does not designate a mere interference of wave but it designates an interference of vibration energy, so that it can be defined as "mutual interference with energy exchange". Such phenomenon can be found in the performance of the guitar and violin other than the piano. More specifically, when playing the guitar or violin, the string, provided next to the actually plucked string, resonates to the vibration of the actually plucked string, which allows generation of the musical sound having the pleasant sound quality. However, the conventional apparatus cannot accurately reproduce sounds having characteristics affected by the pitch difference or the foregoing mutual interference among strings.